Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint=true, openWorldHint=true, idempotentHint=true, destructiveHint=false, covering the safety profile. The description adds context about the connection scope (own grant, separate from organic) and clarifies it returns an id for downstream use. It does not fully describe output format, but the annotations handle operational traits, so this is more than adequate.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is concise, with two clear paragraphs. The purpose is front-loaded, and the routing guidance is in a separate, clearly labeled block. Every sentence adds value without redundancy.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a simple list tool with one parameter and a clear safety profile from annotations, the description covers all necessary context: what it lists, its scope, when to use it, and how it relates to sibling tools. Nothing critical for correct invocation is missing.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so the single parameter (companyId) is fully documented in the schema. The description does not add new parameter details but reinforces the company scope context. Baseline 3 is appropriate since the schema carries the parameter semantics.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool lists X (Twitter) ad accounts on the company's X Ads connection, explicitly distinguishing it from organic X posting and Meta/Facebook ads. It names sibling tools (list_x_ad_campaigns, get_x_ads_performance, list_ad_accounts) to avoid confusion, meeting the criteria for a specific verb+resource with sibling differentiation.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

It provides explicit routing guidance: 'Use first when the user asks about X ads' and explicitly states it is distinct from list_ad_accounts (Meta). It mentions the returned id feeds downstream tools, giving clear when-to-use and when-not-to-use with alternatives.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.